Pathogenicity of fungi associated with leaf spot disease of sweet potato (Ipomea batatas L. (Lam) in Makurdi, Benue State, Nigeria.
Department of Crop and Environmental Protection, Federal University of Agriculture, P.M.B. 2373 Makurdi, Benue State, Nigeria.
Research Article
GSC Biological and Pharmaceutical Sciences, 2020, 11(02), 250-256.
Article DOI: 10.30574/gscbps.2020.11.2.0140
Publication history:
Received on 14 May 2020; revised on 22 May 2020; accepted on 24 May 2020
Abstract:
The screen house experiment was conducted to determine the pathogenicity of leaf spot fungi of sweet potato in Makurdi situated in the Southern Guinea Savannah of Nigeria. The experiment was a completely randomized design with twelve replicates. The variability in pathogenicity of four leaf spot fungi namely: Aspergillus flavus (Link), Aspergillus tamarii (Kita), Macrophomina phaseolina (Tassi), and Fusarium verticillioides (Sacc.) on sweet potato variety TIS-3164 was evaluated in the screen house using the spore suspension of the fungi at 15x 106 spores/ ml on four weeks old plants. All four isolates were pathogenic and induced necrotic symptoms on sweet potato plants. The leaf spot lesions were widest in sweet potato plants inoculated with A. tamarii (9 cm) followed by F. verticollioides (5 cm), A. flavus (4 cm) and M. phaseolina (3.20 cm). Sweet potato plants inoculated with spore suspension of the test fungi recorded significantly (P < 0.05) lower number of leaves with sweet potato plants inoculated with F. verticillioides recording the least number of leaves (30.75). At 4weeks after planting (WAP), the application of the spore suspension of A. tamarii produced significantly lower leaf area of 5.56cm2. At 4 weeks after inoculation (WAI), percentage leaf defoliation was highest on sweet potato plants inoculated with A. flavus (44.50 %) and least when sweet potato plants were inoculated with M. phaseolina (34.30 %). The inoculation of the sweet potato plants with all test fungi had no significant effect on the vine length. The study demonstrated the pathogenicity of all four test fungi on sweet potato.
Keywords:
Pathogenicity; Sweet potato; Leaf spot; Lesion; Symptoms.
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Copyright © 2020 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0
